The meanings of words are determined by the way in which they are used.
Syntax is determined by the way people actually write and talk.
Prescriptive grammarians can yell and talk all they want, but it will still work that way, just as it always has. “They,” for example, is a plural pronoun because people used it that way. It can become a singular pronoun in certain circumstances for no better reason than that, surprise, people use it that way.
I do want grammarians and grammar teachers to be a bit conservative about the language. They shouldn’t be early adopters of every new way of expressing a thought. But uptight prescriptions are just silly, and can, nay should be ignored.
(I think much the same way about artistic and literary value.)